Undercutter



1933- H. McFARLAND El AL 1,928,697

UNDERCUTTER Filed Jan. 7, 1931 2 Sheets-Sheet l 1933. H. McFARLANb ET AL 1,928,597

UNDERCUTTER Filed Jan. 7. 1931 2 Sheets-Sheet 2 in u 6 7C tol Patented Oct. 3, 1933 UNDERCUTTER vHebe! McFarland, Lakewood, Ohio, and Claude i A. Herman, Bridgeport, 'Conn.,,assignor s to The Martindale Electric Company, Cleveland, Ohio, 21 corporationof .Ohio

I Application January 7, 1931. Serial No. 507,290

7, Claims.

This inventionrelates toimprovements in'undercutters for cleaning out the slots or grooves between commutator bars on directtcurrent motors and dynamos. g e p One of the objects of the 'invention'is the provision of apparatus of this kind which shall have numerous adjustments for accommodating it to commutators of different size, and. for enabling the operator to follow the linesof the commutator bars even though they may be more or less out of correct alignment.

Another object is the provision of a special mounting for the operating motor, providing one or more of the desired adjustments of the cut- 1 ting tool.

Another object is the provision of means for turning thev tool standard without disturbing any of the other adjustments.

Other objects and features of novelty will appear aswe proceed with the description of that form of the invention which, for the purposes of the present application we have illustrated in the accompanying. drawings, .in which Figure 1 is a perspective viewof a'mechanism embodying the invention, shown in operative re- 5 Fig. 5 is a diagrammatic view showing the cutter shaft 'in an inclined position foroperat'ion upon an exceptionally largecommutator;

While the apparatus constituting the invention may be constructed and adapted forum in conmounted, we prefer to, employ a" special machine frame comprising an I-beam 10, supported upon end "feet 11, The upper flanges of the beam are machined fiatjso asto-constitute a machine "T 5 bed 12. ':'On 'this bed there is mounted a fixed support 13 carrying a work center -14, and an adjustablesupport15 carryinga work center 16, the latter center being adapted to be moved 1ongitudinally in its support and clamped imam, justed position by any known ordesi'red means. The support 15 isadapted' to (beheld in various positions of adjustment .by bolts 17 takinguin'to holes 18 in the machine bed, and for further insuring proper; alignment of the .center ,16 the junction with a lathe in which the work is to be centrally thereto and slidably fitting into a groove 20 in the bottompf thesupport 15. In Fig. l we have shown the shaft 21 of an armature 22 mounted between the centers 14 and 16, the armature including a commutator 23, A

The undercutter apparatus, which is adapted to be mounted on a lathe or on the workholding frame abovedescribed, comprises a base plate 24 having a series of holes 25 therethrough by means of which the plate may be bolted to the bed 12 or other support; By providing a number of holes 25 in alignment the base plate 24 may be positioned substantially to suit the work holding frame, that'is to bring'the cutting tool substantially into vertical alignment with the work centers.

standard, this collar forming a part of an'adjusting arm31." Near its outerend the arm 31 is provided with anarcuate slot 32 through which protrudesa stud 33 mounted in the base plate 24; A 'nut34 onthe stud serves as a lock tohold thearm 31 in' adjustedposition. On its outer extremity this arm '31 has pivoted thereto an eye bolt 35 which extends transversely of the base plate through a perforation in a bracket 36 thatis attached 'to one edge of the base plate. The per- Ioration in the bracket .36 is large enough to accommodate a collar 3'7 which surrounds the .bolt.35 and has shoulders on either side 0f the bracket 36, and is provided with a knurled operating disc or, wheel 38.

The collar 37 is inter.-

nally'threa'ded to-receive the threads on bolt 35, Hence, when the disc 38 is turnedthe bolt 3 5 i s moved .inone direction or the other and'the standard 27 is turned about its axis, assuming of course that the nut 34 has been first loosened.

Above thecollar'30, and bearing upon the base vplate ,24.throu'gh theintermediacy of "that collar,

sec"

thereis .a nut 39 having "threaded engagement with thestandard 27 and provided with a hand- =wheel 40, by means of which the nut may be turned." Sincethestandard is held from rotation by the key 29, atall times except when the arm31 is being swung for adjustment purposes, rotation of the nut 39, willcause the standard 27 to move up or down, depending upon the direction of rota- .tionof the nut. 1

1,55 machine bed may=have. a steel strip 19 secured IO n't he upper en 1 motor againstniovement. loosened the motor obviously maybe pushed inprotrudes out of the frame in a forward direction and is arranged to be turned by means of a crank 48. Theslide 43 carrying the rack 44.is there fore adapted to be shiftedl'back and forth upon; the slide support 42. In'order tojprovide stopsfor the slide, we attach thereto-a bracket 49 having a smooth opening to receive-a rod 50 that is secured at its ends to the slide support 42 .by means of brackets 51. two adjustable stop collars 52 which can be set at the desired pointsalong the length of the rod and held in such positions. by 'set. screws or the like. The stop 49, of, course, engages thesecollars at the ends of itstravel.

Power for driving the cutter is furnished preferably by an electric motor-53, which may be mounted in some suitable manner for bodily movement in a direction ,at right angles to the direction of movement of the slide. In the pres ent instance this is accomplished by mounting the motor casing, which is cylindrical, in a cylindrical clamp or split ring 54 having flanges at its adjacent ends which may be drawn together tightly by bolts or other f astenings 55 in order to'hold the When the bolts55 are wardly or pulled outwardly more or less so as to effect exact positioningof the cutter.

s While it may not-be essential in'all cases, we. prefer to mount the clamp 54to have tilting movement about; an axis parallel to the line ofjmovement of the slide'43'." As illustratedherein we may employ for this purpose'a bracket 56 having I a flanged base attached to the slide 43 by studs 57 or the like. The vertical fiat portion of the bracket has formed therein two arcuate slots 58 into which extend studs 59 that are set intov threaded openings in "the clamp. 54.1When the studs 59, are loosened the motor may be shifted bodily to'some other angular position, as indicated forinstancein Fig. 5, and the studs 59 tightened again to hold the motor in that position.

To the rear end of. the housing of motor 53 we bolt a bearing support.60 in which is contained the shaft 61 that is clutched to and constitutesa continuation of the motor shaft. .On the outer extremity of the shaft61,is a saw or'a rotary cutter 62 0f the proper thickness. Since the slots in commutators vary more or less in width it is nec sary to make the cutter 62 removable and replaceable, sothat a cutter of the desired thickness maybe selected and mounted upon the shaft 61 to suit the particular job in hand.

Beneaththe base plate 2.4, there is mounted "upon the threaded standard 2'7 a, v lock nut or ring 63 radial projections 64 for convenience in operation. This nut, when threaded up against the bottom of .base plate 24, pulls downwardly upon nut 39 and causes it to press firmly against collar 30 andthroughthe intermediacy of that collar against base plate 24, thereby preventing unintentional movement of the nut 39.

I Theoperation of. the, invention will bB'ObViOllS to those skilled in the art from'a'perusal' of the l above. description of the mechanism. After the work is mounted between the work centers 14, 16,

j mutator groove. If it does not, the operator then loosens nut 34 and operates d'isc 36 to swing the On the rod 50 there are The operator then tightens nut'34, loosens lock the base plate 24 is secured tothe bed 12 of the frame in a position about midway between the ends of the commutator, and suchthat the cutter 62 will stand approximately above the line of centers 14, 16. Then the operator loosens bolts 55, and by moving the motor 53 inward or outward, he bringsthe cutter 62 into register with the uppermost groove of the commutator, although above the same. Now grasping the handle of the crank 48 the operator oscillates it and moves the slide 43 back and forth, causing the cutter 62 to make its traverse over the commutator and observing whether or not in such traverse the cutter remains in alignment with the uppermost comstandard 2'7 slightly, thereby changing the direction of movement of the slide 43' sufficiently to cause the cutter 62 to follow the desired path. nut 63 and turns hand-wheel 40 in the proper direction to lower standard 2'7 sufiiciently to bring cutter 62 into cutting position. The motor 53 may thenbe started and the'crank 48 operated to reciprocate the rotating cutter, and thus clean out 190 one commutator slot. While the cutter is at one extremity of its movement, beyond the commutator, the operator turnslthe latter on its'center's a distance sufficient to bring the next slot uppermost, or in alignment withthe cutter, when the slideis again caused to reciprocate so as to clean out another slot, and so on until the work is completed. V,

"We have disclosed herein a further adjustment which is not required in all cases, but which is no sometimes desirable, particularly where exceptionally large commutators are to be treated. We refer to the means forswinging the motor about an; axis parallel to the direction of movement of the slide. In Fig. 5' such a commutator is indicated at 65. The motorshaft is indicated at 66 and the cutter at 6'7, Thejshaft 66 is set at the desired .upon the distance of the cutter away from the 'verticalline through the center of commutator 65. After the parts are properly set the opera- M tion ofl'cutting is the same as where the cutter is caused to stand directly above the center of the commutaton.

' In the foregoing description we have necessarilygone somewhat into detail in order to exio plain fully the particular embodiments of the invention herein illustrated, butwe desire it to'be understood that. such detail disclosures are not to be construed as amounting to limitations, except as they may be included in the appended claims. 1'

1 Having thus described our invention, we claim: l 1. A machine of the class described comprising a shaft, a cutting tool mounted on said shaft, a slide carrying said shaft, a slide support for said a slide arranged substantially at right angles to said shaft, a'threaded standard upon which said supportis mounted, arigid guide through which said standard is adapted to slide, means for holding 'the'standard against rotation, anut mounted on said standard above said guide by-the rotation of which said standard iscaused to move vertically in said guide, and 'a'lock'nut on said standard below said guide.

,7 2. A machine of the classdescribed comprising ashaft, a cutting tool mounted onsaidshaft, a 1450 slide carrying said shaft, a slide support for said slide arranged substantially at right angles to said shaft, a threaded standard upon which said support is mounted, said standard having a longitudinal keyway therein, a rigid guide through which said standard is adapted to slide, an arm having a key extending into said keyway, said arm being swingableabout the axis of said standard for turning the latter through a small angle, and a nut threaded upon said standard above said guide for raising and lowering the standard.

3. In an undercutter, work centers, a shaft ar- 7 ranged substantially at right angles to the said centers, a cutting tool mounted on said shaft above said centers, said tool lying substantially in a plane through said centers, a slide carrying said shaft, a slide support for said slide arranged substantially at right angles to said shaft, an electric motor on said slide in driving relation with said shaft, a threaded standard upon which said support is mounted, a rigid guide through which said standard is adapted to slide, and a wheel with a threaded hub mounted on said driving relation with said shaft, means for. moving said slide support toward and away from the work, and separate means for moving said cutting tool with respect to said slide in a direction at right angles to the direction ofmovement of the slide.

5. In a machine of the class described, .work centers, an electric motor arranged with its shaft at right angles to the said centers, a cutting tool carried by said motor above said centers and operatively connected with said shaft, said tool lying substantially in a plane through said centers, a horizontal slide, a slide support, and a clamp on said slide within which said motor is held for adjustment toward and away from the work. I

6. In a machine of the class described, work centers, an electric motor arranged with its shaft at right angles to the said centers, a cutting tool carried by said motor above said centers and operatively connected with said shaft, said tool lying substantially in a plane through said centers, a horizontal slide, a slide support, a cylindrical clamp on said slide within which said motor is held for-adjustment toward and away from the work, and means on said slide for securing said clamp in any one of a series of different angular positions about an axis parallel with the line of movement of the slide,

'7. A machine of the class described comprising a shaft, a cutting tool mounted on said shaft, a slide carrying said shaft, a slide support for said slide arranged substantiallyat'right angles to said Shaft, a standard upon which said support is mounted, said standardbeing vertically adjustable and having a longitudinal keyway therein, a rigid'guide through which said standard is movable in its vertical adjustment, and an arm having a key extending into'said keyway, said arm being swingable about theaXis of said standard for turning the latter through a small angle;

HEBEB, MQFARLAND. CLAUDE A. HERM N. 

